Ortho-hydroxyazo dyes and process for producing the same



Patented Oct. 18, 1938 UNITED STATES ORTHO-HYDROXYAZO DYES AND PROCESS FOR PRODUCING THE SAME Walther Benade, Dessau in Anhalt, Germany, as-

signor to General Aniline Works, Inc., York, N. Y., a corporation of Delaware No Drawing. Application December rial No. 181,381. In Germany 11 Claims.

This invention relates to the manufacture of dyes which dye wool by the chroming process by coupling the diazo compounds of 2-aminobenzene-l-carboxylic acids which contain a sulfonic acid group with a propyl or butyl ester of 2-hydroxynaphthalene-G-carboxylic acid. The lastnamed compounds are obtainable by esterifying the 2-hydroxynaphthalene-6-carboxylic acid described in U. S. Patent No. 1,593,816 with a propyl or butyl alcohol. The dyes yield on wool dyed by the chroming process red dyeings which are characterized by their good properties of fastness.

As compared with the known dye l-aminobenkene-2-carboxylic acid- 2-hydroxynaphthalene-3- carboxylic acid isobutyl ester the dyes have the advantage of a better solubility in water. The first-named dye is not suitable for dyeing textiles on account of its extremely low solubility in water. As compared with the known dye 2- aminobenzene 1 carboxylic acid 4 sulfonic acid- 2-hydroxynaphthalene the dyes of this invention have an improved fastness to fulling.

The following examples illustrate the invention, the parts being by weight:-

Example 1.--21.7 parts of Z-aminobenzene-lcarboxylic acid-5-sulfonic acid are stirred with 200 parts of water and after addition of 10 parts of hydrochloric acid of 12 B. are diazotized with 6.9 parts of sodium nitrite. .The diazo compound is allowed to flow into a solution of 24 parts of 2-hydroxynaphthalene-6-carboxylic acid normal-propyl ester, 6 parts of sodium hydroxide and parts of sodium carbonate in about 700 parts of water at 0 C. The formation of dye is complete in a short time. After it has been worked up and dried in the usual manner the dye is a red powder freely soluble in water and dyeing wool by the chroming process red tints of good properties of fastness.

Example 2.To a solution of parts of 2- hydroxynaphthalene-fi-carboxylic acid isobutyl ester, 6 parts of sodium hydroxide and 15 parts of sodium carbonate in about 800 parts of water is added at 0 C. a diazo compound made from 21.7 parts of 2-aminobenzene-1-carboxylic acid- 4-su1fonic acid, 6.9 parts of sodium nitrite and 10 parts of hydrochloric acid of 12 B. in about 300 parts of water. When coupling is complete, the dye formed is isolated and dried. It dyes wool by the chroming process red tints of good properties of fastness.

Example 3.The diazo compound prepared as described in Example 1 from 21.7 parts of 2- aminobenzene-l-carboxylic acid-5-sulfonic acid is coupled at 0 C. with a solution of 25 parts of PATENT OFFICE New 23, 1937, Se- January 13,

2-hydroxynaphthalene-6-carboxylic acid normalbutyl ester, 6 parts of sodium hydroxide and 15 parts of sodium carbonate in about 800 parts of water. The dye worked up and dried in the usual manner is a red powder and dyes wool by the chroming process red tints of good fastness.

What I claim is:--

1. The dyes which correspond to the general formula GOOH wherein R means an alkyl radicle of the group consisting of propyl and butyl, said dyes dyeing wool by the chroming process red dyeings of good fastness.

2. The dyes which correspond to the general formula HOaS COOH OH said dyes dyeing wool by the chroming process 3 red dyeings of good fastness.

3. The dye which corresponds to the formula oooomomon,

and coupling the diazo compound with 2-hydroxynaphthalene-G-carboxylic acid normal-propyl ester.

7. The dyes which correspond to the general formula ooopmomom),

HOsS

OOOH OH said dyes rendering red dyeings of good fastness on wool by the chroming process.

8. The dyes which correspond to the general formula CO0.CH2CH2CHQCH3 COOH 0H said dyes rendering red dyeings of good fastness on wool by the chroming process.

9. The dye which corresponds to the formula COOH OH said dye rendering red dyeings of good fastness on wool by the chroming process.

10. The process which comprises diazotizing a 2-aminobenzene-1-carboxylic acid-sulfonic acid and coupling the diazo compound with 2-hydroxynaphthalene-G-carboxylic acid iso-butyl ester.

11. The process which comprises diazotizing a 2-aminobenzene-l-carboxylic acid-sulfonic acid and coupling the diazo compound with Z-hydroxynaphthalene-B-carboxylic acid normal-butyl ester. 20

WALTHER BENADE. 

